Mercurial air-pump.



Patented Dec. I9, I899.

H. S. MAXIM.

MERCURIAL AIR PUMP.

(Applicauon filed Apr. 28. 1899-) (No Model) I-IIRAM STEVENS MAXIM, OF LONDON, ENGLAND.

NIERCURIAL AIR-PUMP.

SPECIFICATION forming part of Letters Patent No. 639,593,- dated December 19, 1899.

Application filed April 28, 1899- To ctZZ whom it may concern:

Be it known that I, HIRAM STEvENs MAXIM, chevalier of the Legion of Honor, civil and mechanical engineer, a citizen of the United States, residing at 18 Queens Gate Place, London, in the county of Hiddlesex, England, have invented certain new and useful Improvements in Mercurial Air-Pumps, of which the following is a specification.

This invention relates to mercurial airpumps, and especially to those of the kind known as the Geissler and the 'Sprengel.

According to mypresent invention I provide the head-that is to say, the enlarged upper portion of the bent tube into which the mercury flows from a reservoirwith a hollow float, which is adapted to act as an automatic device for checking the inlet of the mercury to the said head when its flow through the pump is unduly retarded or is stopped. The said hollow float is so constructed that the mercury, when its flow is not checked, will pass through the float in a finely divided or comminuted condition, whereby any air or gas contained in the mercury will be effectually liberated, so as to be easily removed from the head by suitable means, such as an air-pump connected therewith. The entrance of air and impurities into the mercurial pump with the mercury is thus avoided.

In order that my said invention may be clearly understood and readily carried into effect, I will proceed to describe the same more fully with reference to the accompanying drawing, which shows a sectional elevation of my improved mercurial air-pump.

A is the head, which is connected by the pipe A to the chamber 13.

O is one of the fall-tubes.

D is a vessel into which the lower ends of the fall-tubes dip and from which the mercury flowing through the pump is returned to the head A for use over again by any suitable elevating apparatus.

E is the float, which is shown in the form of a tube or cylinder of glass, provided at its ends with cork or other stoppers 6. These stoppers are perforated or otherwise formed to permit the mercury to flow through the said float. The intervening space between the two stoppers contains particles of glass e or other suitable substance that will not flerial No. 714,821. (No model.)

have a detrimental effect 011 the mercury, the particles being of such a size and shape that there will be left between them innumerable small interstices, through which the mercury will flow in a very fine state of division. I find that glass beads answer my purpose very well. The said float, together with the beads it contains, is made sufficiently buoyant to float on the mercury within the head A, with its upper stopper a short distance below the inlet-nozzle a, through which the mercury enters the said head. The portion of the upper stopper that lies immediately below the said inlet-nozzle is nnprovided with perforations. When the inflow of the mercury becomes in excess of the outflow, the level of the mercury in the head A will rise, and thereby elevate the float and bring the imperforate portion of its upper stopper against the said inlet-nozzle (1, thus checking the inflow until the level of mercury in the said head falls again and allows the float to come out of contact with the said inlet-nozzle. The float is also furnished with circumferential ribs or rings 6 to act as guides.

ment the flow of the mercury into the falltubes is rendered intermittent and enables the stream of mercury flowing through them to be in the condition of a succession of large drops or pistons, which effectually act to eX- haust the air or gas from the lamp-globes or other vessels that are for this purpose connected with the chamber B by the pipe B.

A is a stopper of glass or other appropriate material by which the mouth of the head A is closed. It is made hollow to contain hygroscopic material, such as phosphoric anhy drid, the inlet-nozzle a extending vertically through said stopper and having a stop-cock ct for controlling the flow of the mercury to the head A.

a is another stop-cock on the stopper for controlling the passage a leading to an airpump, by which the space above the mercury in the head A is kept in a vacuous condition. The mouth of the head A is trumpet-shaped, so that a space a is left around the portion of the stopper entering said head to receive m ercury or other substance to make a hermetic joint at this part.

The tube A is made in straight sections, which are connected together by collars or hands a composed of india-rubber or other appropriate material. The lower horizontal section is furnished with a stop-cock a. to enable the passage of the mercury in the head A and its tube to be stopped and permit the mercury in the vertical section leading to the chamber B to be discharged into a vessel G when a stop-cock a is opened. This enables the mercury in the head A and its tube to remain undisturbed while the other part of the apparatus is being emptied of its mercury. hen the apparatus is in operation, the stopcock a is closed and the stop-cock 6L6 opened. The aforesaid vessel G is provided with a pipe g, furnished with a stop-cock g, leading to an apparatus for elevating the mercury in the vessel G to the head A or to a reservoir from which such head is supplied.

What I claim is- 1. In a mercurial air-pump having a head for the mercury communicating with the vessels to be exhausted and with fall tubes through which the mercury from said head descends to remove the air from the said vessels; the combination with the said head and its inlet-nozzle, of a hollow float containing particles of material that will not detrimentally affect the mercury and through which the mercury will flow as it leaves the inletnozzle and thereby become comminuted, as

descends to remove the air from the said vessels; the combination with the said head and its inlet-nozzle, of a hollow cylindrical float containing glass beads held in place by perforated stoppers at the ends of the said cylindrical float and of guide-pieces on the exterior of said float, substantially as described and for the purpose specified.

3. In a mercurial air-pump having a head for the mercury communicating with the vessels to be exhausted and wit-h fall tubes through which the mercury from said head descends to remove the air from the said vessels; the combination with the said head, of a hollow stopper to contain hygroscopic material, of an inlet-nozzle on said stopper, of a float for regulating the passage of the mercury through the inlet-nozzle, and of means for comminuting the mercury entering said head, substantially as described and for the purpose specified.

4:. In a mercurial air-pump having a head for the mercury communicating with the vessels to be exhausted and with fall tubes through which the mercury from said head descends to remove the air from the said vessels; the combination with the said head, of a hollow stopper to contain hygroscopic material, of an inlet-nozzle on said stopper, of a float for regulating the flow of mercury through said inlet-nozzle, of means for comminuting the mercury entering said head and of means for keeping the space in said head above the mercury in a vacuous condition, substantially as described and for the purpose specified.

In testimony whereof I have hereunto set my hand, in presence of two subscribing witnesses, this 14th day of April, 1899.

IIIRAM STEVENS MAXIM.

Witnesses:

J. COLLINS, WALTER J. SKERTEN. 

